The following abbreviations are utilized throughout this document:
B-BEB B-component of a Backbone Edge Bridge
CCM Continuity Check Message
CFM Connectivity Fault Management
CBP Customer Backbone Port
ESP Ethernet Switched Path
IEEE Institute of Electrical and Electronics Engineers
I-SID Backbone Service Instance Identifier
LAN Local Area Network
LBM/LBR Loopback Message/Loopback Reply
LTM/LTR Linktrace Message/Linktrace Reply
MAC Media Access Control
MEP Maintenance association End Point
MIP Maintenance association Intermediate Point
MP Maintenance Point (MEP or MP)
PBB Provider Backbone Bridge
PBBN Provider Backbone Bridged Network
PBB-TE Provider Backbone Bridges Traffic Engineering
PIP Provider Instance Port
SAP Service Access Point
TLV Type, Length, Value
VID VLAN Identifier
Ethernet has become the undisputed leading Local Area Network (LAN) technology. This achievement stems from the intrinsic characteristics of the technology: simple, cheap, easy to manage, and backward compatible.
Telecommunication operators and carriers are looking at the possibility of reaping the same benefits by replacing the SONET/SDH infrastructure of their metro and backbone networks with an Ethernet-based packet transport infrastructure since data services now account for the bulk of traffic. However, metro and backbone networks have quite different requirements than enterprise LANs. Consequently, Ethernet technology requires specific enhancements if it is to fulfill these carrier-grade requirements. Current work carried out at the Institute of Electrical and Electronics Engineers (IEEE) on the Provider Backbone Bridge Traffic Engineering (PBB-TE) concept is intended to amend the Ethernet 802.1Q standard to provide a true carrier-grade packet transport solution based on Ethernet. (See, IEEE P802.1Q-2006/D0.1, Draft IEEE Standard for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks).
PBB-TE (i.e., IEEE P802.1Qay/D0.0, Draft Standard for Local and Metropolitan Area Networks—Virtual Bridged Local Area Networks—Amendment?: Provider Backbone Bridges—Traffic Engineering, May 2007) proposes a simple, connection-oriented solution. PBB-TE maintains the inherent advantages of Ethernet, while addressing the deficiencies of Ethernet as a carrier-class packet transport protocol. It builds upon the concepts brought forth in the amendments to IEEE 802.1Q to provide a scalable solution, mainly the network separation of PBB in IEEE P802.1ah/D3.8, Draft Standard for Local and Metropolitan Area Networks—Virtual Bridged Local Area Networks—Amendment?: Provider Backbone Bridges, October 2007.
Connectivity Fault Management (CFM) is a very important component in enhancing Ethernet with carrier-grade functionality. IEEE has specified protocols, procedures, and managed objects to support connectivity fault management. (See, IEEE P802.1ag/D8.1, Approved Standard for Local and Metropolitan Area Networks—Virtual Bridged Local Area Networks—Amendment 05: Connectivity Fault Management, June 2007). These protocols, procedures, and managed objects enable discovery and verification of the path, through bridges, and LANs (taken for frames addressed to and from specified network users) as well as detection of a connectivity fault and isolation of the fault to a specific bridge or LAN.